Deformed Mesh Thermal Ground Plane

ABSTRACT

Some embodiments include a thermal ground plane comprising a first casing layer and a second casing layer where the outer periphery of the first casing layer and the outer periphery of the second casing layer are bonded to each other. The thermal ground plane including a working fluid disposed within the first casing layer and the second casing layer. The thermal ground plane may also include a permeable wick disposed between the first casing layer and the second casing layer; and a deformed mesh disposed between the first casing layer and the permeable wick, the deformed mesh comprising a mesh with deformed mesh portions that form vapor channels and nondeformed mesh portions that form liquid channels.

BACKGROUND

Recent developments of higher integration and higher performance electronic devices have led to increased heat dissipation requirements. Similarly, electronic device miniaturization has led to increased heat generation density. This is becoming increasingly important with the miniaturization and advancements in smart phones and other similar devices as well as with electronic vehicles.

SUMMARY

Some embodiments include a thermal ground plane comprising a first casing layer and a second casing layer where the outer periphery of the first casing layer and the outer periphery of the second casing layer are bonded to each other. The thermal ground plane including a working fluid disposed within the first casing layer and the second casing layer. The thermal ground plane may also include a permeable wick disposed between the first casing layer and the second casing layer; and a deformed mesh disposed between the first casing layer and the permeable wick, the deformed mesh comprising a mesh with deformed mesh portions that form vapor channels and nondeformed mesh portions that form liquid channels.

In some embodiments, deformed mesh comprises a plurality of fibers woven together. In some embodiments, the deformed mesh comprises a plurality of mesh layers. In some embodiments, the deformed mesh portions are mesh portions that have been compressed. In some embodiments, the deformed mesh comprises an array nondeformed mesh portions. In some embodiments, the deformed mesh comprises a mesh with a first surface that is substantially flat and a second surface that has been deformed to include a plurality of ridges or pillars.

In some embodiments, the deformed mesh is disposed between the first casing and the second casing with the second surface positioned toward the first casing. In some embodiments, the deformed mesh is disposed between the first casing and the second casing with the second surface positioned toward the permeable wick.

In some embodiments, the thermal ground plane may include a planar mesh disposed between the deformed mesh and the permeable wick.

In some embodiments, the permeable wick includes a plurality of pillars.

In some embodiments, the deformed mesh includes an internal artery.

In some embodiments, the deformed mesh includes a first mesh layer with a first pore size and a second mesh layer with a second pore size that is different than the first pore size.

In some embodiments, the deformed mesh comprises a metallic polymer, metal coated polymer, ceramic coated polymer, ALD coated polymer, copper coated steel, copper coated stainless steel.

In some embodiments, the permeable wick comprises permeable structures selected from the list consisting of a woven mesh, a nonwoven mesh, a plurality of pillars, a plurality of particles, one or meshes, a plurality of channels, a plurality of micropillars, and a plurality of microchannels.

Some embodiments include a thermal ground plane that includes a first casing layer and a second casing layer. In some embodiments, the outer periphery of the first casing layer and the outer periphery of the second casing layer are bonded to each other. A working fluid may be disposed within the first casing layer and the second casing layer. The thermal ground plane may include a plurality of structures disposed within the first casing layer and the second casing layer. In some embodiments, each of the plurality of structures include a mesh structure and an internal artery disposed within the mesh structure.

In some embodiments, each mesh structure comprises a plurality of mesh layers.

In some embodiments, the internal artery extends from the first casing to the second casing. In some embodiments, the internal artery is surrounded by the mesh structure. In some embodiments, each internal artery extends along an entire length of each respective mesh structure. In some embodiments, the internal artery comprises a plurality of internal arteries disposed within each mesh structure.

In some embodiments, the thermal ground plane may include a second mesh disposed between at least two of the mesh structures, the second mesh comprising a mesh having a higher permeability than the mesh structures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an example diagram of a thermal ground plane (TGP) according to some embodiments.

FIG. 2 is a diagram of a TGP according to some embodiments with a vapor structure, a liquid structure, and a mesh disposed between the vapor structure and the liquid structure.

FIG. 3A is a diagram of a TGP according to some embodiments.

FIG. 3B is a diagram of a TGP according to some embodiments.

FIG. 4A and FIG. 4B illustrate the deformation of a deformed mesh according to some embodiments.

FIG. 5A is an illustration of a TGP with a liquid structure comprising a mesh and a permeable wick according to some embodiments.

FIG. 5B is an illustration of a TGP with a liquid structure comprising a mesh and a permeable wick according to some embodiments.

FIG. 6A is an illustration of a TGP with a liquid structure comprising a mesh and a permeable wick according to some embodiments.

FIG. 6B is an illustration of a TGP with a liquid structure comprising a mesh and a permeable wick according to some embodiments.

FIG. 7A is an illustration of a TGP with the perimeter of the mesh bonded to a solid wall according to some embodiments.

FIG. 7B is an illustration of a sideview of a TGP with the perimeter of the mesh bonded to the second casing layer.

FIG. 8A is an illustration of a side view of a TGP with a vapor structure including a folded mesh according to some embodiments.

FIG. 8B is an illustration of a stamping process for making a vapor structure.

FIG. 9A is an illustration of a sideview of a TGP with a deformed mesh that forms liquid channels and vapor channels according to some embodiments.

FIG. 9B is an illustration of a sideview of a TGP with a deformed mesh that forms liquid channels and vapor channels according to some embodiments.

FIGS. 10A, 10B, and 10C. illustrate the process of making a deformed mesh according to some embodiments.

FIG. 11A is an illustration of a side view of a TGP according to some embodiments.

FIG. 11B is an illustration of a side view of a TGP according to some embodiments.

FIG. 12A is an illustration of a side view of a TGP according to some embodiments.

FIG. 12B is an illustration of a side view of a TGP according to some embodiments.

FIGS. 13A, 13B, and 13C illustrate the process of making a deformed mesh according to some embodiments.

FIG. 14 is an illustration of a side view of a TGP according to some embodiments.

FIGS. 15A-15E illustration a process for creating a liquid wick according to some embodiments.

FIG. 16A is an illustration of a side view of a TGP according to some embodiments.

FIG. 16B is an illustration of TGP according to some embodiments.

FIGS. 17A, 17B, and 17C illustrate the process of making a deformed mesh according to some embodiments.

FIG. 18A is an illustration of a side view of a TGP having a permeable wick formed within the second casing layer according to some embodiments.

FIGS. 18B and 18C illustrate the process of making a deformed mesh according to some embodiments.

FIG. 19A is an illustration of a side view of a TGP having a permeable wick formed in a soft material that is disposed on the second casing layer according to some embodiments.

FIGS. 19B and 19C illustrate the process of making a deformed mesh according to some embodiments.

FIG. 20A is an illustration of a side view of a TGP according to some embodiments.

FIG. 20B is an illustration of a top view of the TGP according to some embodiments.

FIG. 20C is an illustration of a side view of a TGP according to some embodiments.

FIG. 21A is an illustration of a side view and FIG. 21B is an illustration of a top view of a TGP according to some embodiments.

FIG. 22A is an illustration of a side view and FIG. 22B is an illustration of a top view of a TGP according to some embodiments.

FIG. 23A is an illustration of a side view and FIG. 23B is an illustration of a top view of a TGP according to some embodiments.

FIG. 24A is an illustration of a side view and FIG. 24B is an illustration of a top view of a TGP according to some embodiments.

FIG. 25 is an illustration of a top view of a TGP according to some embodiments.

FIG. 26A is an illustration of a side view of the TGP along line A.

FIG. 26B is an illustration of a side view of the TGP along line B.

FIG. 26C is an illustration of a side view of the TGP along line C.

FIG. 27A is an illustration of a side view of a TGP according to some embodiments.

FIG. 27B is an illustration of a side view of a TGP according to some embodiments.

FIG. 27C is an illustration of a side view of a TGP according to some embodiments.

FIG. 28A is an illustration of a side view of a TGP according to some embodiments.

FIG. 28B is an illustration of a side view of a TGP according to some embodiments.

FIG. 28C is an illustration of a side view of a TGP according to some embodiments.

FIG. 29A is an illustration of a side view of a TGP with liquid structures and vapor structures according to some embodiments.

FIG. 29B is an illustration of a side view of a TGP with liquid structures and vapor structures according to some embodiments.

FIG. 30 is an illustration of a top view of a TGP having liquid structures and vapor structures according to some embodiments.

FIG. 31 is an illustration of a side view of a TGP with liquid structures and vapor structures according to some embodiments.

FIG. 32A is an illustration of a side view of a TGP with a vapor core that may include a layer of deformed mesh according to some embodiments.

FIG. 32B is an illustration of a side view of a TGP with a vapor structure and a liquid structure comprising microparticles and/or nanoparticles according to some embodiments.

FIGS. 33A, 33B, and 33C illustrate a steps for fabricating a TGP with microparticles and/or nanoparticles according to some embodiments.

FIGS. 34A, 34B, and 34C illustrate a side view of a liquid structure of a TGP according to some embodiments.

FIG. 35A is a top view of a TGP with regions of high permeability and regions of low permeability according to some embodiments.

FIG. 35B is a side view of a TGP with regions of high permeability and regions of low permeability according to some embodiments.

FIGS. 37A and 37B illustrate a side view of at least a portion of a TGP with multiple regions of high permeability that

FIG. 38 illustrates a side view of a liquid structure of a TGP 3800 according to some embodiments. may be separated in-plane by impermeable walls according to some embodiments.

DETAILED DESCRIPTION

A thermal ground plane is disclosed, that includes a first casing layer (e.g., first casing layer), a second casing layer (e.g., bottom casing), liquid structures, and vapor structures. Either or both the liquid structures, and vapor structures may include a deformed structure.

A thermal ground plane is a type of vapor chamber, in which the first casing layer and the second casing layer form a hermetic seal, and within that sealed region is a wick which is permeated with a liquid. The liquid may be in thermodynamic equilibrium with a saturated vapor phase. The vapor phase may permeate a cavity which is supported by some vapor structure. When heat is applied at any location, the liquid evaporates and increases the temperature of the vapor by a small amount. That increase in temperature results in a local area of increased pressure, which then generates a flow of the vapor away from the high pressure region, and thereby carries heat away by convection. The heat is rejected away from the vapor core in the colder regions when the vapor condenses, and the condensate is pulled back to the hot region by capillary forces within the wick. The utilization of convection allows the thermal ground plane system to achieve high amounts of heat transfer with low temperature gradients, and thereby a high effective thermal conductivity. The capillary forces in the wick may be high enough to overcome any drag forces in the wick, drag forces in the vapor phase, pressure drops associated with phase change, and hydrostatic effects of gravity. The drag forces are influenced by thermosphysical properties of the fluids and the effective permeability of the wick and vapor core structures.

In some embodiments, a thermal ground plane my enclose a working fluid. The working fluid may generate a gas-liquid phase change under an atmosphere in between the first casing and the second casing. The working fluid may, for example, comprise water, alcohol, alternative fluorocarbon or the like. The alternative fluorocarbon, for example, may follows the list established by the US Environmental Protection Agency (EPA). In some embodiments, the working liquid be an aqueous compound. In some embodiments, the working liquid be water.

FIG. 1 is a diagram of a TGP 100 according to some embodiments. In this example, the TGP 100 includes a first casing layer 110, a second casing layer 115, a liquid structure 120, and/or a vapor structure 125. The TGP 100, for example, may operate with evaporation, vapor transport, condensation, and/or liquid return of water or other cooling media for heat transfer between the evaporation region 130 and the condensation region 135. The first casing layer 110 may include copper, polyimide, polymer-coated copper, copper-cladded Kapton, etc. The second casing layer 115 may include copper, polyimide, polymer-coated copper, copper-cladded Kapton, etc. In some embodiments, the first casing layer 110 and the second casing layer 115 of the TGP 100 may be sealed together using solder, laser welding, ultrasonic welding, electrostatic welding, or thermo-pressure compression or a sealant 140. In some embodiments, the first casing layer 110 and the second casing layer 115 of the TGP 100 may include the same or different materials.

The evaporation region 130 and the condensation region 135 may be disposed on the same layer: the first casing layer 110 or the second casing layer 115. Alternatively, the evaporation region 130 and the condensation region 135 may be disposed on different layers of the first casing layer 110 and the second casing layer 115

In some embodiments, the vapor structure 125 and/or liquid structure 120 may be formed from an initial structure (e.g., a mesh) that has been deformed into various geometric shapes that may improve thermal transport, the flow permeability, the capillary radius, the effective thermal conductivity, the effective heat transfer coefficient of evaporation, and/or the effective heat transfer coefficient of condensation. In some embodiments, the initial structure may include multiple layers of mesh.

In some embodiments, the outer periphery of the first casing layer 110 and the outer periphery of the second casing layer 115 may be sealed such as, for example, hermetically sealed.

FIG. 2 is a diagram of a TGP 200 according to some embodiments with a vapor structure 125, a liquid structure 120, and a planar mesh 210 disposed between the vapor structure 125 and the liquid structure 120. In some embodiments, the planar mesh 210 may, for example, enhances the capillary effect, permeability effect, or the heat transfer associated with phase change between liquid and vapor.

The planar mesh 210, for example, may comprise a woven mesh or a nonwoven mesh. The planar mesh 210, for example, may comprise a metallic polymer, metal coated polymer, ceramic coated polymer, ALD coated polymer, copper coated steel, copper coated stainless steel, etc. A nonwoven mesh may comprise a mesh where the fibers are randomly distributed. A nonwoven mesh may comprise a sheet with ordered or nonordered array of holes etched in the sheet. The sheet may be metallic or polymer. A woven mesh may comprise a ordered distribution of fibers.

In some embodiments, the liquid structure 120 may comprise a porous structure. In some embodiments, the liquid structure 120 may produce capillary pressure that allows liquid to flow through the liquid structure 120.

The planar mesh 210, for example, may separate the vapor structure 125 and the planar mesh 210. The planar mesh 210, may enhance the capillary effect, permeability effect, or the heat transfer associated with phase change between liquid and vapor.

A mesh, for example, may comprise a woven mesh or a nonwoven mesh. A mesh, for example, may comprise a metallic polymer, metal coated polymer, ceramic coated polymer, ALD coated polymer, copper coated steel, copper coated stainless steel, etc. A nonwoven mesh may comprise a mesh where the fibers are randomly distributed. A nonwoven mesh may comprise a sheet with ordered or nonordered array of holes etched in the sheet. The sheet may be metallic or polymer. A woven mesh may comprise a ordered distribution of fibers.

FIG. 3A is a diagram of a TGP 300 according to some embodiments. The vapor structure 125 includes a deformed mesh 305. The deformed mesh 305 may include a planar member that has been deformed to include a plurality of pillars 310. The plurality of pillars 310 may comprise corrugated pillars. Each or a majority of the plurality of pillars 310 may extend from the first casing layer 110 to the planar mesh 210. In some embodiments, vapor may flow between the plurality of pillars 310. In some embodiments, deformed mesh 305 may comprise any material that can be deformed into a shape and/or that can support the vapor cavity. In some embodiments, the deformed mesh 305 may comprise copper, steel, copper-coated steel, other metals, copper-coated polymer, ceramic coated polymer, and/or ceramic coated metal. In some embodiments, the deformed mesh 305 may be encapsulated with copper.

In some embodiments, the deformed mesh 305 may be solid. In some embodiments, the deformed mesh 305 may be porous, which may, for example, allow vapor to flow between cavities defined by the first casing layer 110 and the deformed mesh 305.

In some embodiments, the plurality of pillars may be supported by particles of material 315 under, below, above, or on both sides of the plurality of pillars 310, as shown in the side view of TGP 350 shown in FIG. 3B. In FIG. 3B the particles of material are placed within the deformations that create the plurality of pillars 310.

In some embodiments, the plurality of pillars 310 may be formed with the deformed mesh 305 by depressing pillar shapes into the deformed mesh 305. The deformed mesh 305 may undergo either inelastic or plastic deformation, as shown in FIG. 4A and FIG. 4B. Prior to deformation, the deformed mesh 305 may be in a planar state and placed between top press 405 and a bottom press 410 as shown in FIG. 4A. The top press 405, for example, may include a plurality of positive extensions and the bottom press 410 may include a plurality of corresponding recesses. The top press 405 and the bottom press 410 may be pressed together deforming the deformed mesh 305 as shown in FIG. 4B.

FIG. 5A is an illustration of a TGP 500 with a liquid structure 120 comprising a mesh 510 and a permeable wick according to some embodiments. In some embodiments, the mesh 510 may include a material having a plurality of holes. These holes, for example, may have a diameter of less than about 40 microns. The mesh 510 may be bonded to the permeable wick with electroplating, thermo-sonic bonding, or thermo-compressive bonding. In some embodiments the mesh 510 mesh may be formed by flattening a woven mesh, by electroplating, and/or by etching a planar member. In some embodiments, the mesh 510 may comprise copper, polyimide, polyester, polycarbonate, glass, other metals, other polymers, or other ceramics. In some embodiments, the mesh 510 may be substantially flat.

In some embodiments, the permeable wick may include a plurality of pillars 505 disposed on the second casing layer 115. The plurality of pillars 505 may, for example, be uniformly or nonuniformly distributed. The plurality of pillars 505 may, for example, be a plurality of micropillars. The plurality of pillars 505 may be formed, for example, by mechanical scribing, milling, chemical etching, photolithography, etching, and/or electroplating.

The TGP 500 may include a vapor structure 125 that comprises a plurality of particle structures 515 that each include a plurality of particles. The plurality of particles may include sintered particles.

FIG. 5B is an illustration of a TGP 550 with a liquid structure 120 comprising a mesh 510 and a permeable wick according to some embodiments. The permeable wick may include a plurality of particles 525 such as, for example, particles comprising copper, glass, metals, other ceramics, or composites.

FIG. 6A is an illustration of a TGP 600 with a liquid structure 120 comprising a mesh 510 and a permeable wick according to some embodiments. The permeable wick may include one or more meshes 520.

FIG. 6B is an illustration of a TGP 650 with a liquid structure 120 comprising a mesh 510 and a permeable wick according to some embodiments. Although the permeable wick in the figure is shown with a plurality of plurality of pillars 505 any type of permeable wick may be used such as, for example, the plurality of particles structures 515, the one or more meshes 520, etc. The mesh 510, may include a textured surface 610. In some embodiments, the textured surface may be textured on the side of the mesh 510 facing the vapor structure 125. The textured surface may, for example, help pull liquid into the textured area by capillary forces associated with texturing, which may increase the area associated with heat evaporation.

When liquid evaporates within a TGP, heat may flow through the vapor-liquid interface. By extending the area of the vapor-liquid interface, the thermal resistance of evaporation may be reduced. In some embodiments, the mesh 510 may be textured with a textured surface 610 on the vapor-side such that liquid may be pulled away from the pores into the textured area by capillary forces associated with texturing, which may increase the area associated with heat evaporation. In some embodiments, the textured surface 610 may be formed by chemically etching the mesh 510 with a non-uniform etch process. In some embodiments, the textured surface 610 may be formed by laser or mechanical scribing, sintering particles to the surface of the planar mesh, patterning the planar mesh with out-of-plane features by photolithography, and/or etching or deposition, non-lithography based deposition through a template such as inverse opal structures or plating through randomly distributed defects in a film, non-templated anisotropic deposition techniques such as rapid plating, and/or non-templated anisotropic etching techniques such as de-alloying, etc.

FIG. 7A is an illustration of a TGP 700 with the perimeter of the mesh 510 bonded to a solid wall 705 such that, for example, the vapor-liquid interface is constrained to the pores within the mesh 510 and cannot form along the perimeter. The capillary force of such vapor liquid interface, for example, can keep vapor from impinging into the liquid structure 120. In some embodiments, the solid wall 705 can include porous material where the pore size is smaller or similar size to the capillary diameter of the mesh 510. In some embodiments, the solid wall 705 can include foam, sintered particles, micropillars, mesh, etc

FIG. 7B is an illustration of a sideview of a TGP 700 with the perimeter of the mesh 510 bonded to the second casing layer 115. The mesh 510 may include one or more bends around the perimeter to connect the mesh 510 to the second casing layer 115.

FIG. 8A is an illustration of a side view of a TGP 800 with a vapor structure 125 including a folded mesh 805 according to some embodiments. In some embodiments, the folded mesh 805 can be compressed or folded at folds 810 in a non-uniform fashion such that each layer of material is of different dimensions. In some embodiments, the folded mesh 805 can include any porous material or any solid material that is made to be porous before or after folding. In some embodiments, the folded mesh 805 can be made of multiple layers of mesh. In some embodiments, the folds 810 in the folded mesh 805 may form ribs within the vapor structure 125 that extend along y-direction (into the page).

In some embodiments, the ribs can be formed into pillars 820 by compressing the folded mesh at intervals in the y-direction, as shown in FIG. 8B. The pillars 820 can be formed by folding and/or by pressing the folded mesh 805 between an upper press 860 and a lower press 865 to form pillars 820.

FIG. 9A is an illustration of a sideview of a TGP 900 with a deformed mesh 902 that includes deformed mesh portions 905 and nondeformed mesh portions 910 according to some embodiments. In some embodiments, the deformed mesh portions 905 may be formed in a pattern.

The deformed mesh portions 905 may form vapor channels 915 between the nondeformed mesh portions 910. The deformed mesh 902 may be disposed within the TGP 900 on a permeable wick 920. The deformed mesh 902, for example, may include either woven or nonwoven mesh. The vapor channels 915 may occur within gaps between nondeformed mesh portions 910 and the first casing layer 110. The deformed mesh portions 905 (and/or the vapor channels) may be created by any deformation process such as, for example, the deformation process shown in FIGS. 10A, 10B, and 10C.

In some embodiments, the deformed mesh 902 may include multiple layers of the same type of mesh (e.g., the same thread count or same pore sizes) stacked on upon another or multiple layers of different types of mesh (e.g., different thread counts or different pore sizes) stacked one upon another. In some embodiments, the deformed mesh 902 may include spacing layers between different mesh layers.

In some embodiments, the nondeformed mesh portions 910 (e.g., the liquid channels) may comprise any of a variety of different configurations such as, for example, pillars (as shown in FIG. 9B), elongated channels (e.g., having a rectangular cross section), or overhangs. In some embodiments, the height of the nondeformed mesh portions 910 (e.g., the liquid channels) can be greater than the sum of the thickness of the deformed mesh portions 905 and the permeable wick 920.

FIG. 9B is an illustration of a top view of the TGP 900 according to some embodiments. The nondeformed mesh portions 910 are shown in array of nondeformed mesh portions 910 within the mesh. The nondeformed mesh portions 910 (e.g., the liquid channels), for example, may have a width less than about 10, 5, 2, 1, or 0.5 mm, a center-to-center pitch less than about 10, 5, 2, 1, or 0.5 mm, and/or a height less than about 2, 1, 0.5, 0.2, or 0.1 mm. The nondeformed mesh portions 910 (e.g., the liquid channels), for example, may have a cross-section that is square, rectangle, circular, oval, or star-shaped.

In some embodiments, the deformed mesh portions 905 may be formed by compressing multiple layers of mesh through a compressive mask such as, for example, as shown in FIGS. 10A, 10B, and 10C. In some embodiments, the mask is formed of copper, steel, other metal, other ceramic, or polymer.

In some embodiments, the deformed mesh portions 905 may be bonded to the permeable wick 920. In some embodiments, the permeable wick 920 may be a woven or nonwoven mesh layer as shown in FIG. 11A with or without a planar mesh layer. In some embodiments, the permeable wick 920 may include a plurality of pillars, a plurality of particles, one or meshes, a plurality of channels, a plurality of micropillars, a plurality of microchannels, etc.

The deformed mesh portions 905 may be created, formed, compressed, etc. such as, for example, by the deformation process shown in FIGS. 10A, 10B, and 10C. A top press 1005 and a bottom press 1010 may press one or more nondeformed meshes 1015 to create deformed mesh 902.

FIG. 11A is an illustration of a side view of a TGP 1100 with a deformed mesh 902 according to some embodiments. The TGP 1100 includes a deformed mesh portions 905, a planar mesh 1110, and/or a permeable wick. The planar mesh 1110 may ensure the mesh effect in the nondeformed mesh portions 910 (e.g., the liquid channels) may maintain high capillary performance. In some embodiments, the pores in the planar mesh 1110 may be smaller than the pores in mesh that comprise the deformed mesh portions 905. The permeable wick may include a mesh 1105 such as, for example, a woven mesh or a nonwoven mesh.

FIG. 11B is an illustration of a side view of a TGP 1150 with a deformed mesh 902 according to some embodiments. The TGP 1150 includes a deformed mesh portions 905, a planar mesh 1110, and/or a permeable wick that includes pillars 1115 and walls 1120 disposed on the second casing layer 115. In some embodiments, the walls 1120 may include the same shape, material, size, etc. as the pillars 1115. Both, for example, can be made by hot embossing. The walls 1120, for example, may bound the pillars 1115 or portions of the permeable wick. The walls 1120, for example, may ensure that the high capillary pressure will prevent ingress of vapor into the pillars 1115.

In some embodiments, the deformed mesh portions 905 may or may not be bonded with the first casing layer 110. In some embodiments, the deformed mesh portions 905 may or may not be bonded with the second casing layer 115. In some embodiments, bonding may include thermocompression bonding, thermosonic bonding, electroplating, etc.

FIG. 12A is an illustration of a side view of a TGP 1200 according to some embodiments. The deformed mesh portions 905 is flipped relative to the orientation within the TGP of the deformed mesh portions 905 shown in FIG. 11B. The compressed portion of the deformed mesh portions 905, for example, may be disposed on or bonded with the first casing layer 110. The nondeformed mesh portions 910 (e.g., the liquid channels), for example, may extend away from the first casing layer 110 toward the planar mesh 1110 and/or toward the pillars 1115. The ends of the nondeformed mesh portions 910 (e.g., the liquid channels), for example, may be coupled with the planar mesh 1110.

FIG. 12B is an illustration of a side view of a TGP 1250 according to some embodiments. The TGP 1250, for example, may include a deformed mesh 1205 with upper deformations and lower deformations. The upper deformations, for example, may include liquid channels 1210 in the form of mesh pillars and vapor channels 1215 in the voids between the mesh pillars. The lower deformations, for example, may include liquid channels 1220 in the form of mesh pillars and vapor channels 1225 in the voids between the mesh pillars.

In some embodiments the layers of the deformed mesh 1205 may include meshes with different mesh weave types, thread count, wire diameter, or mesh material. In some embodiments, the lower deformations may be selectively compressed in the same or a different manner as the selective compression of the upper deformations.

The deformed mesh 1205 may be created by the deformation process shown in FIGS. 13A, 13B, and 13C. A top press 1305 and a bottom press 1310 may press a plurality of nondeformed meshes 1315 to create deformed mesh 1205.

FIG. 14 is an illustration of a side view of a TGP 1400 according to some embodiments. The TGP 1400 may include a first deformed mesh 1405 forming a vapor structure. The first deformed mesh 1405, for example, may include a plurality of layers. The TGP 1400 may include a second deformed mesh 1410 forming a liquid structure. The second deformed mesh 1410, for example, may include a plurality of layers. A planar mesh 1415 may be disposed between the first deformed mesh 1405 and the second deformed mesh 1410. The planar mesh 1415, for example, may ensure the mesh effect in the non-compressed regions maintains high capillary performance.

In some embodiments, the pitch between deformations of the first deformed mesh 1405 may be larger than the pitch between deformations of the second deformed mesh 1410. In some embodiments, the height of the deformations of the first deformed mesh 1405 may be larger than the height of the deformations of the second deformed mesh 1410. In some embodiments, the number of deformations of the first deformed mesh 1405 may be fewer than the number of deformations of the second deformed mesh 1410.

FIGS. 15A-15E illustration a process for creating a liquid wick according to some embodiments. The process starts with a mesh 1505 as shown in FIG. 15A. The mesh 1505 may be planar. The mesh 1505 may be flattened as shown in FIG. 15B. Additionally or alternatively, the planar mesh may be formed by photo-lithography and etching or electroplating, by etching through a template, by selective decomposition such as de-alloying, etc. The mesh 1505 may I include a plurality of woven or nonwoven fibers.

The mesh 1505 may be deformed to include a pattern having a plurality of pillars using a press fixture with male and female sides as shown in FIG. 15C. The mesh 1505 may be coupled with the second casing layer 115 (or substrate) as shown in FIG. 15D and FIG. 15E.

FIG. 16A is an illustration of a side view of a TGP 1600 according to some embodiments. The TGP 1600 may include a deformed mesh 1605 is similar to deformed mesh 1405 with upper deformations and lower deformations. The upper deformations, for example, may include liquid channels in the form of mesh pillars 1610 and vapor channels in the voids 1615 between the mesh pillars 1610. The lower deformations, for example, may include liquid channels in the form of mesh pillars 1620 and vapor channels in the voids 1625 between the mesh pillars.

The deformed mesh 1605 may include small deformations 1635 compressed into the compressed portions of the deformed mesh 1605. The small deformations 1635, for example, may extend out of plane relative to the compressed portions of the deformed mesh 1605 as shown in FIG. 16B. As another example, the small deformations 1635, for example, may be in plane relative to the compressed portions of the deformed mesh 1605. In some embodiments, the deformed mesh 1605 may be patterned by deformation including compression, folding, etching, plating, boding, etc.

The deformed mesh 1605 can be formed using a press as shown in FIGS. 17A, 17B, and 17C.

FIG. 18A is an illustration of a side view of a TGP 1800 having a permeable wick formed within the bottom layer 1805 according to some embodiments. The permeable wick may include a plurality of indentations 1810 that form a plurality of microchannels. In some embodiments, the indentations 1810 can be formed by cold-pressing or hot-pressing a shape into a bottom layer 1805 as shown in FIGS. 18B and 18C. In some embodiments, the bottom layer 1805 may include copper, polymer, copper-clad polymer, or other elastic materials. A planar mesh 210 may be disposed on the deformed bottom layer 1805.

FIG. 19A is an illustration of a side view of a TGP 1800 having a permeable wick formed in a soft material 1915 that is disposed on the bottom layer 1905 according to some embodiments. The permeable wick may include a plurality of indentations 1910 that form a plurality of microchannels. In some embodiments, the soft material may include hydrogen-annealed copper, polymer, thermoplastic polyimide, polysulfone polymers, polyethylene naphthalate, copper-clad polymer, or other elastic materials. In some embodiments, the indentations 1910 can be formed by cold-pressing or hot-pressing a shape into a soft material 1915 as shown in FIGS. 19B and 19C.

FIG. 20A is an illustration of a side view of a TGP 2000 with a deformed mesh according to some embodiments. The TGP 2000 may include a mesh structure 2005 from undeformed portions of the deformed mesh. Vapor channels 2010, for example, may be formed by the deformed portions of the deformed mesh and the mesh structure 2005. The mesh structure 2005, for example, may extend to the first casing layer 110.

The physics of vapor transport through the vapor channel 2010 show that the pressure drop of the vapor may be proportional to the cube of the channel height. This non-linear behavior, for example, may mean that if the height of the vapor channels 2010 is increased in some regions and reduced in regions parallel to the flow, then there may be a net benefit. Such a condition may be met by arteries within the vapor channel 2010. The mesh structure 2005 may comprise a plurality of mesh layers stacked one upon another forming the mesh structure 2005. FIG. 20B is an illustration of a top view of the TGP 2000.

In some embodiments, the vapor channel 2010 may be defined by the first casing layer 110, a mesh layer, and the sides of one or more mesh structure 2005. Some vapor channels 2010 may also be defined by the edge of the TGP 2000.

FIG. 20C is an illustration of a side view of a TGP 2050 according to some embodiments. The TGP 2050 may be similar to the TGP 2000 with the mesh structures 2015 that do not extend to the first casing layer 110.

FIG. 21A is an illustration of a side view and FIG. 21B is an illustration of a top view of a TGP 2100 according to some embodiments. The liquid structures 2005 includes a mesh support pillar 2115 that extends from the top of the liquid structures 2005 to the first casing layer 110.

FIG. 22A is an illustration of a side view and FIG. 22B is an illustration of a top view of a TGP 2200 according to some embodiments. The liquid structures 2005 may include a mesh support pillar 2115 that extends from the top of the liquid structures 2005 to the first casing layer 110. The vapor channels 2010 may include a vapor-support pillar 2215 that extends from the vapor channels 2010 to the first casing layer 110.

FIG. 23A is an illustration of a side view and FIG. 23B is an illustration of a top view of a TGP 2300 according to some embodiments. The TGP 2300 includes liquid structures 2005 that have portions that extend to the first casing layer 110 and other portions that do not extend to the first casing layer 110 with a gap 2310. Vapor may flow along the arteries in the vapor channels 2010 defined by the liquid structures 2005 as shown by arrow 2335. Vapor may also flow between arteries in the vapor channels 2010 through gaps 2310 within the liquid structures 2005. Thus, liquid may flow through the liquid structures 2005 and vapor may flow across the liquid structures 2005 through the gaps 2310. The gaps 2310 in the liquid structures 2005 are not aligned. In this example, the gaps 2310 in the liquid structures 2005 are substantially not aligned across the TGP 2400.

FIG. 24A is an illustration of a side view and FIG. 24B is an illustration of a top view of a TGP 2400 according to some embodiments. In this example, the gaps 2310 in the liquid structures 2005 are substantially aligned across the TGP 2400.

FIG. 25 is an illustration of a top view of a TGP 2500 according to some embodiments. The TGP 2500 includes a number of different arrangements of arteries, liquid structures, and/or vapor structures. FIG. 26A is an illustration of a side view of the TGP 2500 along line A where the vapor channel 2010 includes a bottom mesh layer and the liquid structures 2005 either extend to the first casing layer 110 or extend nearly to the first casing layer 110 such as, for example, with mesh support pillars 2115. In some embodiments, the vapor channel 2010 may be defined by the first casing layer 110, the bottom mesh layer 2605, and the sides of one or more liquid structures 2005. Some vapor channels 2010 may also be defined by the edge of the TGP 2500.

FIG. 26B is an illustration of a side view of the TGP 2500 along line B. Along this portion of the TGP 2500 includes a bottom mesh layer 2605 on the second casing layer 115.

FIG. 26C is an illustration of a side view of the TGP 2500 along line C. Along this portion of the TGP 2500 that does not include bottom mesh layer 2605 on the second casing layer 115 and includes vapor channel 2010 and mesh structure 2005. In some embodiments, the bottom mesh layer 2605 may include sintered particles, micropillars, microchannels, etc.

In some embodiments, an evaporation region (e.g., evaporation region 130) may be disposed at or near portions of the TGP 2500 shown in FIG. 26A or FIG. 26B.

FIG. 27A is an illustration of a side view of a TGP 2700, which is similar to the TGP 2500 shown in FIG. 26A according to some embodiments. The TGP 2700 may include a capping mesh 2705 on top of the bottom mesh layer 2605. The capping mesh 2705, for example, may have a pore size that is smaller than the pore size of the bottom mesh layer 2605 and/or the pore size of the mesh comprising the mesh structure 2005.

FIG. 27B is an illustration of a side view of the TGP 2730, which is similar to the TGP 2500 shown in FIG. 26B according to some embodiments. The TGP 2730 may include a capping mesh 2705 on top of the bottom mesh layer 2605. The capping mesh 2705, for example, may have a pore size that is smaller than the pore size of the bottom mesh layer 2605.

FIG. 27C is an illustration of a side view of the TGP 2760, which is similar to the TGP 2500 shown in FIG. 26C according to some embodiments. The TGP 2760 may include a capping mesh 2705 on top of one layer of the mesh that comprise the mesh structure 2005. The capping mesh 2705, for example, may have a pore size that is smaller than the pore size of the mesh that comprise the mesh structure 2005.

FIG. 28A is an illustration of a side view of the TGP 2800 according to some embodiments. The TGP 2800 is similar to the TGP 2760 shown in FIG. 27C. The TGP 2800 may include a capping mesh 2805 on top of at least the bottom mesh 2820 that comprise the mesh structure 2005. The capping mesh 2805 may include one or more wall portions 2810. The wall portions 2810 may extend around the perimeter of the bottom mesh 2820 and/or the mesh structure 2005. In some embodiments, the wall portions may be formed by a solid material or one which has a low pore size (e.g., less than the pore sized of the capping mesh 2805 or bottom mesh 2820 or any mesh in the mesh structure 2005), such that the capillary force of the capping mesh 2805 and wall portions 2810 together may prevent or restrict the ingress of vapor into the mesh structure 2005. In some embodiments, the wall portions 2810 can be a simply connected geometry or have multiple cutout regions according to artery type designs. In some embodiments, the capping mesh 2805 may enhance the capillary force in a through-plane direction.

FIG. 28B is an illustration of a side view of the TGP 2830 according to some embodiments. The TGP 2830 is similar to the TGP 2760. The TGP 2830 may include a capping mesh 2840 on top of at least one layer of the bottom mesh 2820 that comprises at least a portion of the mesh structure 2005. The capping mesh 2840 may also be coupled with the second casing layer 115.

FIG. 28C is an illustration of a side view of the TGP 2860 according to some embodiments. The TGP 2800 is similar to the TGP 2760. The TGP 2860 may include a capping mesh 2840 on top of a plurality of the mesh 2820 that comprise the mesh structure 2005 or the entire liquid structure. The capping mesh 2840 may also be coupled with the second casing layer 115.

In some embodiments, the capillary pressure may be low and/or the spacing between features (e.g., pore spacing in mesh structure 2005) may be large such as 75, 100, 150, 200 micron, etc. The capping mesh 2840 my have small feature sizes, such as 1, 5, 10, 25, 50 um etc., which may create higher capillary pressure. For example, the mesh structure 2005 may have a pore size of about 250 microns and the capping mesh 2840 may have a pore size of about 50 microns. As another example, the mesh structure 2005 may have a pore size of about 50 microns and the capping mesh 2840 may have a pore size of about 5-10 microns.

FIG. 29A is an illustration of a side view of a TGP 2900 with deformed mesh 2910 and internal arteries 2905 according to some embodiments. The deformed mesh 2910 may include internal arteries 2905. The internal arteries, for example, may allow for high permeability of the liquid flow. The internal arteries, for example, may be surrounded by mesh that comprises the deformed mesh 2910. The internal arteries, for example, may be surrounded by porous liquid structures such as sintered particles, microposts, etc. In some embodiments, the length of the internal arteries 2905 may extend along the entire length or a substantial portion of the deformed mesh 2910.

FIG. 29B is an illustration of a side view of a TGP 2950 with deformed mesh 2910 and internal arteries 2905 according to some embodiments. The deformed mesh 2910 may include internal arteries 2905 that extend from the first casing layer 110 to the second casing layer 115 (or a permeable wick or a planar mesh). Thus, the internal arteries 2905 may be surrounded by a mesh that defines the liquid structure, the first casing layer 110, the second casing layer 115, and/or liquid structures such as sintered particles, microposts, etc.

In some embodiments, internal arteries 2905 may enhance the thermal resistance of a TGP by a factor of 2.

In some embodiments, the deformed mesh 2910 and the internal arteries 2905 may be disposed upon or beneath a permeable wick. In some embodiments, a planar mesh may be disposed between the deformed mesh 2910 and a permeable wick.

The deformed mesh 2910 may form vapor channels 2915 in between deformed mesh 2910.

FIG. 30 is an illustration of a top view of a TGP 3000 having two different types of deformed mesh structure 2910A, 2910B according to some embodiments. The deformed mesh structure 2910A, for example, may include internal arteries 2905A that extend along a substantially length of the deformed mesh structure 2910A.

The deformed mesh structure 2910B, for example, may include internal arteries 2905B that may not extend along the entire length of the deformed mesh structure 2910B. The internal arteries 2905B may comprise a plurality of internal arteries 2905B with mesh portions 3005 in between. This may, for example, prevent the spreading of vapor along the whole artery if there is ingress of vapor into one of the liquid flow open areas.

FIG. 31 is an illustration of a side view of a TGP 3100 with deformed mesh 2910 and internal arteries 2905 according to some embodiments. In some embodiments, the deformed mesh 2910 may include internal arteries 3110 that includes a wick structure that has a higher porosity than the surrounding mesh comprising the deformed mesh 2910, such as pillars, coarse mesh, particles, etc. The internal arteries 3110, for example, may extend from the first casing layer 110 to the second casing layer 115. The internal arteries 3110, for example, may not extend from the first casing layer 110 to the second casing layer 115.

FIG. 32A is an illustration of a side view of a TGP 3200 with a vapor core 3205 that is formed by a layer of deformed mesh 3210 according to some embodiments. In some embodiments, the deformed mesh 3210 may comprise a single layer. In some embodiments, the deformed mesh 3210 may include a coarse mesh (e.g., a mesh with large pores such as, for example, about 0.5, 1.0, 1.5, 2.0, 2.5, etc. mm). As vapor flows through a porous media (e.g., a mesh), for example, resistance and/or pressure drop may be proportional to the inverse square of the hydraulic radius of the flow. As a result, a deformed mesh 3210 with two small pores, for example, may have much higher resistance than a deformed mesh 3210 with a single larger pore. In some embodiments, the deformed mesh 3210 may support the vapor core.

In some embodiments, the deformed mesh 3210 may extend across a diagonal between the first casing layer 110 and the planar mesh 210 dividing the flow into 2 regions, which may result in an increase in flow resistance. In some embodiments, a diagonal deformed mesh 3210 can be deformed to allow the majority of the flow through a vapor core 3205 with large pores. In some embodiments, wires comprising the mesh of the deformed mesh 3210 can be further deformed to increase the flow area. In some embodiments, the deformation can promote flow in a single direction, while maintaining higher flow resistance in a perpendicular direction. In some embodiments, the TGP vapor core can include multiple different regions with different deformed meshes 3210 to promote the vapor flow in different directions within each region.

In some embodiments, a plurality of particles 3215 may be disposed between the deformed mesh 3210 and the first casing layer

FIG. 32B is an illustration of a side view of a TGP 3250 with a vapor structure 3255 and a liquid structure 3265 defined by microparticles and/or nanoparticles according to some embodiments. The liquid structure 3265 may be defined by a plurality of pillars or structures 3270 formed from microparticles and/or nanoparticles disposed on the second casing layer 115. The vapor structure 3255 may be formed by a plurality of pillars or structures 3260 from microparticles and/or nanoparticles disposed on the first casing layer 110. The width and/or height of the plurality of pillars or structures of the vapor structure 3255 may be larger than either or both the width and/or height of the plurality of pillars or structures of the liquid structure 3265. For example, the plurality of pillars or structures 3260 may be made from particles (e.g., sintering micro/nano particles) with a width about 0.3 mm to about 1.0 mm and/or a height about 0.1 mm to 0.2 mm. The plurality of pillars or structures 3270, for example, may be made from particles (e.g., sintering micro/nano particles) with a width about 0.075 mm to about 0.2 mm. The plurality of pillars or structures 3270, for example, may be made from particles (e.g., sintering micro/nano particles) with a width about 0.02 mm to about 0.075 mm.

In some embodiments, the microparticles and/or nanoparticles may be sintered together to form pillars. In some embodiments, the microparticles and/or nanoparticles may comprise copper, glass, other metals, or other ceramics. In some embodiments, the pillars may include microparticles and/or nanoparticles having different radii. In some embodiments, a fraction of the particles may sinter to bond to the remaining microparticles and/or nanoparticles and form a solid pillar, such as, for example, with copper nanoparticles sintering to seal copper microparticles.

FIGS. 33A, 33B, and 33C illustrate a steps for fabricating a TGP with microparticles and/or nanoparticles according to some embodiments. In some embodiments, a screen printing process may be used. FIG. 33A shows a template 3305 on the second casing layer 115.

FIG. 33B shows a plurality of microparticles and/or nanoparticles placed between the template. In some embodiments, the microparticles and/or nanoparticles can be deposited as a paste that may include microparticles and/or nanoparticles, solvent, and/or binder. In some embodiments, the solvent may include isopropanol, acetone, water, or other organic or inorganic solvents. In some embodiments, the binder may be polyvinyl alcohol, stearic acid, or another binder.

In some embodiments the microparticles and/or nanoparticles may be cleaned of oxides prior to placing the microparticles and/or nanoparticles on the second casing layer 115 using acid vapor, liquid acid, hydrogen bearing gas, or hydrogen-bearing plasma.

In some embodiments, the microparticles and/or nanoparticles may be sintered at elevated temperatures. In some embodiments, microparticles and/or nanoparticles sinter to a mesh layer to form the wick or vapor structure. In some embodiments, the microparticles and/or nanoparticles may be sintered in a vacuum environment, in an inert gas atmosphere, or in a reducing atmosphere. In some embodiments, the pillars formed by sintering may be bonded to a mesh layer at an elevated temperature and/or subsequently bonded to a cladding layer at lower temperature.

FIG. 33C shows the microparticles and/or nanoparticles after the template 3305 has been removed or etched away.

FIGS. 34A, 34B, and 34C illustrate a side view of a wick structure 3400 (or permeable wick) of a TGP according to some embodiments. The wick structure 3400, for example, may be part of a TGP and may include various other wicks, meshes, casing, layers, etc. The wick structure 3400, for example, may include a plurality of high-permeability region 3415 and a plurality of low-permeability regions 3410. In some embodiments, the wick structure 3400 may include a planar mesh 210. The physics of capillary driven liquid flow dictate that wick structures with high permeability (e.g., high-permeability region 3415) may also have high capillary radius locally; and structures with low capillary radius (e.g., low-permeability regions 3410) may also have low permeability. The capillary pressure may be determined by the capillary radius at the vapor-liquid interface, rather than the capillary radius in the regions of the wick that are saturated with liquid. It may be possible to have a region of high permeability completely surrounded by regions of low permeability and high capillary pressure, and in such a case the flowing liquid will experience low flow resistance of the high permeability region as well as the high capillary pressure of the low permeability region. One possible issue that may arise is if a vapor bubble 3420 forms within a high-permeability region 3415, then the vapor bubble 3420 can expand and cause that region of the wick structure 3400 to dry out, shown in FIG. 34B and FIG. 34C. A vapor bubble 3420, for instance, could form from nucleate bubbles in the high-permeability region 3415 or from defects in a low-permeability region 3410.

In the event that a region of high permeability dries out through this mechanism, the vapor can be contained such that the entire wick does not dry out, by having multiple regions of high permeability connected by regions of low capillary radius. Then if one region of high permeability dries out, the vapor/liquid interface will be arrested at the region of low capillary radius, and therefore not spread into the adjacent region of high permeability. Because the regions of low capillary radius are porous, liquid will flow between adjacent regions of high permeability. This structure follows a similar mechanism to the method used to transport fluid up the woody structure of plants through the so-called xylem, while preventing cavitation-so this design of wick can be referred to “artificial xylem”. In some embodiments, the regions of high permeability can be formed by cutting or deforming a mesh, while the regions of low capillary radius can be formed by the un-deformed mesh; in such a manner, liquid flows between adjacent high permeability regions in-plane, as in FIG. 35A and FIG. 35B.

Some TGPs can include other wick structures (e.g. permeable wicks) that can allow in-plane low capillary radius regions and high permeability regions. FIGS. 36A and 36B illustrate a side view of at least a portion of a TGP 3600 with different wick structures according to some embodiments. TGP 3600 includes sintered particle structures 3605 and 3610 which have different densities. TGP 3650 with micropillars 3660 or microchannels with different densities, as shown in FIG. 36B; or foam structures such as inverse opals, dealloyed structures, or randomly distributed pores within a block.

FIGS. 37A and 37B illustrate a side view of at least a portion of a TGP 3700 with multiple regions of high permeability that may be separated by regions of low permeability. TGP 3700, for example, may include in-plane impermeable walls 3705, which may be connected in the through-plane direction by a permeable mesh 3710, and which may allow liquid to flow between adjacent high permeable regions in the through-plane direction. In some embodiments, the high permeability regions may be defined by micropillars. In some embodiments, the impermeable walls and/or the micropillars may be formed by photolithography and/or plating or etching processes. In some embodiments, the mesh is bonded to the pillars in a thermo-sonic, thermo-compressive, or electroplating bonding method; and the second layer of micropillars and walls are grown by electroplating on the first mesh layer, as shown in FIG. 37B.

In some embodiments, the regions of high permeability may have an aspect ratio and/or angle which allows a region in one layer to connect to three or more regions in the upper or lower layer, as shown in FIG. 38 . In some embodiments, there may be more than two layers that make up the through-plane stack.

In some embodiments, the mesh 3710 may include nano-porous scale features, with a maximum pore size of 10 nm, 50 nm 100 nm, 200 nm, etc; in some embodiments the nano-porous mesh is formed for example by track etching, by dealloying glass or metallic alloys, by nano-porous anodizing, by selective etching of self-assembled micelles, by sintering nanoparticles, etc.

FIG. 38 illustrates a side view of a liquid structure of a TGP 3800 according to some embodiments. The TGP 3800 includes a liquid structure comprising a deformed mesh 3810 that may include any number of mesh layers. Although a deformed mesh 3810 is shown, any type of deformed mesh known in the art or shown in this document may be used in the liquid structure. The TGP 3800 may also include vapor structure that may comprise a deformed mesh 3805 that is deformed from a single mesh layer. In some embodiments, a planar mesh 210 may be disposed between the deformed mesh 3810 and the deformed mesh 3810.

The term “permeable wick” may include one or more of a woven mesh, a nonwoven mesh, a plurality of pillars, a plurality of particles, one or meshes, a plurality of channels, a plurality of micropillars, a plurality of microchannels, etc. A permeable wick may also include foam and/or an inverse opal structure.

A term “mesh” may include a plurality of woven fibers (e.g., woven mesh) or a plurality of nonwoven fibers (a nonwoven mesh). A mesh may comprise metallic polymer fibers, metal coated polymer fibers, ceramic coated polymer fibers, ALD coated polymer fibers, copper coated steel fibers, copper coated stainless steel fibers, metal fibers, polymer fibers, copper fibers, stainless steel fibers, copper coated stainless steel, etc. A nonwoven mesh may comprise a mesh with a random distribution of fibers. A nonwoven mesh may comprise a sheet with ordered or nonordered array of holes etched in a sheet, which may be metallic or polymer. A woven mesh may comprise an ordered distribution of fibers. A nonwoven mesh may also include planar sheet formed additively such as: sintering microparticles and/or nanoparticles, electroplating through a template, rapid plating with bubble generation, deposition of metal/polymer/ceramic over a template, anodizing, etc.

Unless otherwise specified, the term “substantially” means within 5% or 10% of the value referred to or within manufacturing tolerances. Unless otherwise specified, the term “about” means within 5% or 10% of the value referred to or within manufacturing tolerances.

The conjunction “or” is inclusive.

The terms “first”, “second”, “third”, etc. are used to distinguish respective elements or blocks or steps. and are not used to denote a particular order of those elements unless otherwise specified or order is explicitly described or required.

Numerous specific details are set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter may be practiced without these specific details. In other instances, methods, apparatuses or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure claimed subject matter.

Embodiments of the methods disclosed may be performed in the operation of such computing devices. The order of the blocks presented in the examples above can be varied—for example, blocks can be re-ordered, combined, and/or broken into sub-blocks. Certain blocks or processes can be performed in parallel.

The use of “adapted to” or “configured to” is meant as open and inclusive language that does not foreclose devices adapted to or configured to perform additional tasks or steps. Additionally, the use of “based on” is meant to be open and inclusive, in that a process, step, calculation, or other action “based on” one or more recited conditions or values may, in practice, be based on additional conditions or values beyond those recited. Headings, lists, and numbering included are for ease of explanation only and are not meant to be limiting.

While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art. 

That which is claimed is:
 1. A thermal ground plane, including: a first casing layer; a second casing layer where outer peripheries of the second casing layer are hermetically sealed with outer peripheries of the first casing layer to form a TGP housing case; a vapor transport layer disposed nearby the first casing layer in the TGP housing case; a vapor transport layer disposed nearby the second casing layer in the TGP housing case; and a working fluid filled in the TGP housing case.
 2. The thermal ground plane according to claim 1, wherein the vapor transport layer comprises a first deformed mesh including: a plurality of vapor channels; a plurality of first deformed mesh parts; and a plurality of first mesh parts that are cross-connected to each other.
 3. The thermal ground plane according to claim 2, wherein the liquid transport layer comprises a second deformed mesh including: a plurality of liquid channels; a plurality of second deformed mesh parts; and a plurality of second mesh parts which are cross-connected to each other.
 4. The thermal ground plane according to claim 3, wherein a plurality of ridges in the first mesh parts are correspondingly stacked between each two of the ridges in the second mesh parts.
 5. The thermal ground plane according to claim 1, wherein the vapor transport layer and the liquid transport layer are formed into an integrated part structure by a compression step.
 6. The thermal ground plane according to claim 3, wherein the working fluid flows through the first mesh parts and the second mesh parts, and the first and second mesh parts are connected, respectively by the first deformed mesh parts and the second deformed mesh parts, wherein the first mesh parts are bonded to the first casing layer, and the second mesh parts are bonded to the second casing layer.
 7. The thermal ground plane according to claim 3, further including a planar mesh structure, which is disposed between the vapor transport layer and the liquid transport layer, to separate the vapor transport layer and the liquid transport layer, wherein the working fluid flows between the planar mesh structure, the vapor transport layer and the liquid transport layer.
 8. The thermal ground plane according to claim 7, wherein the first mesh part contacts an inner surface of the first casing layer, and the first deformed mesh parts include a plurality of first ridge to be a plurality of support pillars for keeping a space between the planar mesh structure and the first casing layer, to form a vapor transmission passage.
 9. The thermal ground plane according to claim 8, wherein the second mesh parts are stacked on the planar mesh structure, and the second deformed mesh parts include a plurality of second ridges to be a plurality of support pillars for keeping a space between the second casing layer and the planar mesh structure.
 10. The thermal ground plane according to claim 3, wherein the first mesh parts are correspondingly stacked on the second mesh parts to form a curved mesh structure.
 11. The thermal ground plane according to claim 1, wherein the liquid transport layer includes at least two mesh structures, each of the mesh structures includes at least one capillary channel which uses capillary phenomena to transport the working fluid.
 12. The thermal ground plane according to claim 3, wherein the first deformed mesh includes a plurality of first fiber parts which are interwoven with each other, and the second deformed mesh includes a plurality of second fiber parts which are interwoven with each other.
 13. The thermal ground plane according to claim 3, wherein the first deformed mesh includes a plurality of first mesh layers stacked on each other, and the second deformed mesh includes a plurality of second mesh layers stacked on each other.
 14. The thermal ground plane according to claim 2, wherein the vapor channels form an internal arterial network.
 15. The thermal ground plane according to claim 7, wherein the planar mesh structure includes a plurality of pores, and the pores include smaller sizes than the vapor channels to prevent the vapor in the vapor channels from flowing into the liquid transport layer.
 16. The thermal ground plane according to claim 1, wherein material of the first and second casing layers, includes a combination of copper, polymer, and composite material of copper and polymer.
 17. The thermal ground plane according to claim 1, wherein the hermetic seal between the first and second casing layers are shaped by thermocompression bonding or laser welding, to form the TGP housing case. 